Such a communication process, and more particularly a packet communication process, is already known in the art, e.g. from Belgian patent no. 905982. Therein the forward signal transmitted by the one outside node is a path setup packet which is used to establish a point-to-point path to the other outside node. Upon the receipt of the path setup packet by an inside node on an input communication path, this node selects a single output communication path in a wanted direction and depending on this selection being successful or not, transmits the packet further or converts it to a backward or so called blocked packet respectively. The blocked packet is transmitted to a preceding node and upon receipt of this packet, this node breaks down its output communication path constituting the above input communication path of the following node.
Because according to this known process a point-to-point path is concerned, the last mentioned input communication path is released if no corresponding output communication path is found in the wanted direction. If the same criterion would be used for a point-to-multipoint path where the input communication path is connected to a plurality of output communication paths in a plurality of directions, the release of this input communication path subsequent to the receipt of a blocked packet would provoke the erroneous release of all the paths. On the other hand, if to avoid such a situation one would use the blocked packet only to inform the outside node having generated the path setup packet that the path setup has been unsuccessful and not as an indication to a node that it has to break down a communication path, the latter would remain in the network as a partly established connection and the last mentioned outside node would not be aware of this fact if, for one or another reason, the blocked packet would get lost.